scholarly journals Mechanical signatures of microbial biofilms in micropillar-embedded growth chambers

Soft Matter ◽  
2016 ◽  
Vol 12 (23) ◽  
pp. 5224-5232 ◽  
Author(s):  
S. C. Chew ◽  
B. Kundukad ◽  
W. K. Teh ◽  
P. Doyle ◽  
L. Yang ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Organic Matter ◽  
Microbial Biofilms ◽  
Growth Chambers

Biofilms are surface-attached communities of microorganisms embedded in an extracellular matrix and are essential for the cycling of organic matter in natural and engineered environments.

scholarly journals Autolysin-Independent DNA Release inStreptococcus pneumoniae in vitroBiofilms

2018 ◽  
Author(s):  
Mirian Domenech ◽  
Ernesto García
Keyword(s):  
Extracellular Matrix ◽  
Quorum Sensing ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Extracellular Dna ◽  
Confocal Laser ◽  
Lytic Enzymes ◽  
Microbial Biofilms ◽  
Dna Release

ABSTRACTBiofilms are defined as layers of cells of microorganisms adhered to the surface of a substrate and embedded in an extracellular matrix and provide an appropriate environment for increased genetic exchange. Extracellular DNA (eDNA) is an essential component of the extracellular matrix of microbial biofilms, but the pathway(s) responsible for DNA release are largely unknown. Autolysis (either spontaneous or phage-induced) has been proposed the major event leading to the appearance of eDNA. The ‘suicidal tendency’ ofStreptococcus pneumoniaeis well-known, with lysis mainly caused by the triggering of LytA, the major autolytic amidase. However, the LytC lysozyme and CbpD (a possible murein hydrolase) have also been shown involved. The present work examines the relationship between eDNA, autolysins, and the formation and maintenance ofin vitropneumococcal biofilms, via fluorescent labelling combined with confocal laser scanning microscopy, plus genetic transformation experiments. Bacterial DNA release mechanisms other than those entailing lytic enzymes were shown to be involved by demonstrating that horizontal gene transfer in biofilms takes place even in the absence of detectable autolytic activity. It had been previously suggested that the quorum sensing systems ComABCDE and LuxS/AI-2 are involved in the production of eDNA as a response to the accumulation of quorum sensing signals, although our immunofluorescence results do not support this hypothesis. Evidence that the release of DNA is somehow linked to the production of extracellular vesicles byS. pneumoniaeis provided.

Development of microbial biofilms on cellulosic fibres for organic matter removal in river water treatment

2021 ◽  
Vol 224 ◽  
pp. 144-153
Author(s):  
Wen-Pei Low ◽  
Mohd Fadhil Md Din ◽  
Fung-Lung Chang ◽  
Siti Nur Fatihah Binti Moideen ◽  
Yee Yong Lee ◽  
...  
Keyword(s):  
Organic Matter ◽  
Water Treatment ◽  
River Water ◽  
Organic Matter Removal ◽  
Microbial Biofilms ◽  
Cellulosic Fibres

Best served small: nano battles in the war against wound biofilm infections

2020 ◽  
Vol 4 (6) ◽  
pp. 567-580
Author(s):  
Joanna Shepherd
Keyword(s):  
Extracellular Matrix ◽  
Antimicrobial Resistance ◽  
Biomedical Applications ◽  
Matrix Proteins ◽  
Current Role ◽  
Global Challenge ◽  
Microbial Biofilms ◽  
Wound Biofilms ◽  
Biofilm Matrix

The global challenge of antimicrobial resistance is of increasing concern, and alternatives to currently used antibiotics or methods to improve their stewardship are sought worldwide. Microbial biofilms, complex 3D communities of bacteria and/or fungi, are difficult to treat with antibiotics for several reasons. These include their protective coats of extracellular matrix proteins which are difficult for antibiotics to penetrate. Nanoparticles (NP) are one way to rise to this challenge; whilst they exist in many forms naturally there has been a profusion in synthesis of these small (<100 nm) particles for biomedical applications. Their small size allows them to penetrate the biofilm matrix, and as well as some NP being inherently antimicrobial, they also can be modified by doping with antimicrobial payloads or coated to increase their effectiveness. This mini-review examines the current role of NP in treating wound biofilms and the rise in multifunctionality of NP.

scholarly journals Large-scale environmental controls on microbial biofilms in high-alpine streams

2004 ◽  
Vol 1 (2) ◽  
pp. 159-171 ◽  
Author(s):  
T. J. Battin ◽  
A. Wille ◽  
R. Psenner ◽  
A. Richter
Keyword(s):  
Organic Matter ◽  
Large Scale ◽  
Landscape Heterogeneity ◽  
Low Flow ◽  
Detection Rates ◽  
Carbon Production ◽  
Microbial Biofilms ◽  
Environmental Controls ◽  
Short Period ◽  
Alpine Stream

Abstract. Glaciers are highly responsive to global warming and important agents of landscape heterogeneity. While it is well established that glacial ablation and snowmelt regulate stream discharge, linkage among streams and streamwater geochemistry, the controls of these factors on stream microbial biofilms remain insufficiently understood. We investigated glacial (metakryal, hypokryal), groundwater-fed (krenal) and snow-fed (rhithral) streams - all of them representative for alpine stream networks - and present evidence that these hydrologic and hydrogeochemical factors differentially affect sediment microbial biofilms. Average microbial biomass and bacterial carbon production were low in the glacial streams, whereas bacterial cell size, biomass, and carbon production were higher in the tributaries, most notably in the krenal stream. Whole-cell in situ fluorescence hybridization revealed reduced detection rates of the Eubacteria and higher abundance of α-Proteobacteria in the glacial stream, a pattern that most probably reflects the trophic status of this ecosystem. Our data suggest low flow during the onset of snowmelt and autumn as a short period (hot moment) of favorable environmental conditions with pulsed inputs of allochthonous nitrate and dissolved organic carbon, and with disproportionately high microbial growth. Tributaries are relatively more constant and favorable environments than kryal streams, and serve as possible sources of microbes and organic matter to the main glacial channel during periods (e.g., snowmelt) of elevated hydrologic linkage among streams. Ice and snow dynamics - and their impact on the amount and composition of dissolved organic matter - have a crucial impact on stream biofilms, and we thus need to consider microbes and critical hydrological episodes in future models of alpine stream communities.

scholarly journals Wildfire-Derived Pyrogenic Carbon Modulates Organic Matter and Microbial Functioning in a Fluvial Ecosystem

2021 ◽  
Author(s):  
Lukas Thuile Bistarelli ◽  
Caroline Poyntner ◽  
Cristina Santín ◽  
Stefan H. Doerr ◽  
Matthew V. Talluto ◽  
...  
Keyword(s):  
Organic Matter ◽  
Freshwater Ecosystems ◽  
Enzymatic Activities ◽  
Pyrogenic Carbon ◽  
Microbial Biofilms ◽  
Doc Concentration ◽  
Research Gap ◽  
Fluvial Ecosystem ◽  
In Fire ◽  
Dom Composition

Wildfires produce large amounts of pyrogenic carbon (PyC), including particulate charcoal, known for its chemical recalcitrance and sorption affinity for organic molecules. Wildfire-derived PyC is highly mobile in the landscape and can be transported to fluvial networks where it may impact natural dissolved organic matter (DOM) and microbial biofilms. The effects of PyC on freshwater ecosystems and carbon cycling therein remain poorly investigated. To address this research gap, we used in-stream flumes with a control vs treatment design (pulse addition of PyC particles). We present evidence that field-aged PyC inputs into river ecosystems can alter dissolved organic carbon (DOC) concentration, DOM composition, pH, and enzymatic activities in benthic biofilms. In stream DOM composition was altered due to leaching of pyrogenic DOM from PyC and possible concurrent sorption of riverine DOM to PyC. DOM changes and increase in pH were associated with changes in enzymatic activities, which reflected preferential usageof recalcitrant over easily available DOM by biofilms. Furthermore, we observed particulate PyC sedimentation on biofilm surfaces, which may further modulate the impacts of PyC. This study highlights the importance of PyC for in-stream DOM propertiesand biofilm functioning with implications for in-stream biogeochemical cycling in fire affected watersheds. <br>

scholarly journals Wildfire-Derived Pyrogenic Carbon Modulates Organic Matter and Microbial Functioning in a Fluvial Ecosystem

2021 ◽  
Author(s):  
Lukas Thuile Bistarelli ◽  
Caroline Poyntner ◽  
Cristina Santín ◽  
Stefan H. Doerr ◽  
Matthew V. Talluto ◽  
...  
Keyword(s):  
Organic Matter ◽  
Freshwater Ecosystems ◽  
Enzymatic Activities ◽  
Pyrogenic Carbon ◽  
Microbial Biofilms ◽  
Doc Concentration ◽  
Research Gap ◽  
Fluvial Ecosystem ◽  
In Fire ◽  
Dom Composition

Wildfires produce large amounts of pyrogenic carbon (PyC), including particulate charcoal, known for its chemical recalcitrance and sorption affinity for organic molecules. Wildfire-derived PyC is highly mobile in the landscape and can be transported to fluvial networks where it may impact natural dissolved organic matter (DOM) and microbial biofilms. The effects of PyC on freshwater ecosystems and carbon cycling therein remain poorly investigated. To address this research gap, we used in-stream flumes with a control vs treatment design (pulse addition of PyC particles). We present evidence that field-aged PyC inputs into river ecosystems can alter dissolved organic carbon (DOC) concentration, DOM composition, pH, and enzymatic activities in benthic biofilms. In stream DOM composition was altered due to leaching of pyrogenic DOM from PyC and possible concurrent sorption of riverine DOM to PyC. DOM changes and increase in pH were associated with changes in enzymatic activities, which reflected preferential usageof recalcitrant over easily available DOM by biofilms. Furthermore, we observed particulate PyC sedimentation on biofilm surfaces, which may further modulate the impacts of PyC. This study highlights the importance of PyC for in-stream DOM propertiesand biofilm functioning with implications for in-stream biogeochemical cycling in fire affected watersheds. <br>

scholarly journals Sources of dissolved organic matter during storm and inter-storm conditions in a lowland headwater catchment: constraints from high-frequency molecular data

2015 ◽  
Vol 12 (14) ◽  
pp. 4333-4343 ◽  
Author(s):  
L. Jeanneau ◽  
M. Denis ◽  
A.-C. Pierson-Wickmann ◽  
G. Gruau ◽  
T. Lambert ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
High Frequency ◽  
Molecular Data ◽  
Water Velocity ◽  
Storm Events ◽  
Microbial Biofilms ◽  
To Come ◽  
Chemical Biomarkers ◽  
High Frequency Sampling

Abstract. The transfer of dissolved organic matter (DOM) at soil–river interfaces controls the biogeochemistry of micropollutants and the equilibrium between continental and oceanic C reservoirs. Understanding the mechanisms controlling this transfer is fundamental to ecology and geochemistry. DOM delivery to streams during storms is assumed to come from the flushing of preexisting soil DOM reservoirs mobilized by the modification of water flow paths. We tested this hypothesis by investigating the evolution of the composition of stream DOM during inter-storm conditions and five storm events monitored with high-frequency sampling. The composition of DOM was analyzed using thermally assisted hydrolysis and methylation (THM) with tetramethylammonium hydroxide (TMAH) coupled to a gas chromatograph and mass spectrometer. In inter-storm conditions, stream DOM is derived from the flushing of soil DOM, while during storm events, the modification of the distribution of chemical biomarkers allows the identification of three additional mechanisms. The first one corresponds to the destabilization of microbial biofilms due to the increase in water velocity, resulting in the fleeting export of a microbial pool. The second mechanism corresponds to the erosion of soils and river banks, leading to a partition of organic matter between particulate and dissolved phases. The third mechanism is linked to the increase in water velocity in soils that could induce the erosion of macropore walls, leading to an in-soil partition between soil microparticles and dissolved phase. The contribution of this in-soil erosive process would be linked to the magnitude of the hydraulic gradient following the rise of the water table and could persist after the recession, which could explain why the return to inter-storm composition of DOM does not follow the same temporal scheme as the discharge. These results are the most important factors in understanding the transfer of nutrients and micropollutants at the soil–river interfaces during the hot moments that are storm events.

Molecular-genetic methods for studying microbial biofilms

Bacteriology ◽  
2020 ◽  
Vol 5 (2) ◽  
pp. 49-55
Author(s):  
E.V. Detusheva ◽  
◽  
P.V. Slukin ◽  
N.K. Fursova ◽  
◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Comparative Study ◽  
Molecular Genetic ◽  
Gene Clusters ◽  
Review Article ◽  
Planktonic Cells ◽  
Microbial Biofilms ◽  
Extracellular Matrix Production ◽  
Matrix Production ◽  
Phenotype Identification

The review article contains information on the clinical significance of microbial biofilms and the main modern molecular genetic methods used to study microbial biofilms: comparative study of genome, transcriptome and proteome of planktonic cells and biofilms; genetic control of biofilm extracellular matrix production; analysis of the contribution of individual genes and gene clusters to the formation of the biofilm phenotype; identification of microorganism species in polymicrobial biofilms. Key words: microbial biofilms, molecular genetic methods, genome, transcriptome, proteome, microbial species identification

scholarly journals Sources and transfer mechanisms of dissolved organic matter during storm and inter-storm conditions in a lowland headwater catchment: constraints from high-frequency molecular data

2015 ◽  
Vol 12 (4) ◽  
pp. 3349-3379 ◽  
Author(s):  
L. Jeanneau ◽  
M. Denis ◽  
A.-C. Pierson-Wickmann ◽  
G. Gruau ◽  
T. Lambert ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
High Frequency ◽  
Molecular Data ◽  
Water Velocity ◽  
Storm Events ◽  
Microbial Biofilms ◽  
Chemical Biomarkers ◽  
Dissolved Phase ◽  
Transfer Mechanisms

Abstract. The transfer of dissolved organic matter (DOM) at soil–river interfaces controls the biogeochemistry of micropollutants and the equilibrium between continental and oceanic C reservoirs. Then determining the transfer mechanisms of DOM is of main importance for ecological and geochemical reasons. Is stream DOM the result of the flushing of pre-existing soil DOM reservoirs activated by the modification of water flow paths? The evolution of the chemical composition of stream DOM investigated by thermally assisted hydrolysis and methylation (THM) using tetramethylammonium hydroxide (TMAH) coupled to a gas chromatograph and mass spectrometer (THM-GC-MS) during inter-storm conditions and five storm events with a high-frequency sampling gives new insights on this question. In inter-storm conditions, stream DOM is inherited from the flushing of soil DOM, while during storm events, the modification of the distribution of chemical biomarkers allows the identification of three additional mechanisms. The first one corresponds to the destabilization of microbial biofilms by the increase in water velocity resulting in the fleeting export of a microbial pool. The second mechanism corresponds to the erosion of soils and river banks leading to a partition of organic matter between particles and dissolved phase. The third mechanism is linked to the increase in water velocity in soils that could induce the erosion of macropore walls, leading to an in-soil partitioning between soil microparticles and dissolved phase. The contribution of this in-soil erosive process would be linked to the magnitude of the hydraulic gradient following the rise of water table and could persist after the recession, which could explain why the return to inter-storm composition of DOM does not follow the same temporal scheme as the discharge. Those results are of main importance to understand the transfer of nutrients and micropollutants at the soil–river interfaces during the hot moments that are storm events.

Cardiac myocytes cultured on a basement membrane extract of the ehs tumor

1986 ◽  
Vol 44 ◽  
pp. 270-271
Author(s):  
L. Terracio ◽  
A. Dewey ◽  
K. Rubin ◽  
T.K. Borg
Keyword(s):  
Extracellular Matrix ◽  
Basement Membrane ◽  
Cardiac Myocytes ◽  
Normal Tissue ◽  
Cell Spreading ◽  
Collagen Iv ◽  
Basement Membrane Extract ◽  
Membrane Extract ◽  
Growth Development ◽  
Multicellular Organisms

The recognition and interaction of cells with the extracellular matrix (ECM) effects the normal physiology as well as the pathology of all multicellular organisms. These interactions have been shown to influence the growth, development, and maintenance of normal tissue function. In previous studies, we have shown that neonatal cardiac myocytes specifically interacts with a variety of ECM components including fibronectin, laminin, and collagens I, III and IV. Culturing neonatal myocytes on laminin and collagen IV induces an increased rate of both cell spreading and sarcomerogenesis.

Sign in / Sign up

Export Citation Format

Share Document